A. Field of the Invention
This invention is related to the pigmentation of broiler skin and egg yolk and more particularly, to an extract, a formulation that can be used as broiler feed or drink, and a method for the dosage of such formulation, in order to achieve the right hue that the market requires in the pigmentation of broiler skin and egg yolk.
B. Description of the Related Art
The right color of the broiler skin, and of the egg yolk is widely known as an important quality attribute, which has been taken as synonymous of healthy of the broilers and eggs. However, each region of the world has established its own particular specifications for this parameter. So that the optimum pigmentation for the broiler skin and the egg yolk depends on cultural traditions or preferences (Fletcher, 1992, Poultry Science 71:733-743)).
Therefore, different methodologies to measure the color of both the broiler skin and the egg yolk, have been adopted. As examples of these methodologies are The Roche Colour Fan (RCF) methodology, that is considered a subjective determination, and The Reflectance Chromameter methodology, which is used to make precise objective determinations.
A great effort has recently been made to standardize the available High Performance Liquid Chromatography (HPLC) methodology (Hamilton, 1992, Poultry Science 71:718-724), in order to be able to quantify with more precision the xantophylls contained in the skin of broilers, as well as in the feed and in the egg yolk. However, notwithstanding the advancement of such techniques, it is still difficult to avoid the subjective evaluation of color in the above mentioned products.
Traditionally, the poultry keepers have been incorporating red and yellow pigments (natural or synthetic), in the birds feed.
Synthetic cantaxanthin has been used for decades as active pigment to provide a yellow-orange color to the broiler skin, and to provide intense orange and even rose hues to egg yolk (Geisendorf, 1965).
Rosenberg, in his U.S. Pat. No. 3,539,686 issued in November 1970, demonstrated that it is possible to obtain a wide range of tones going from yellow to red hues in broiler skin and egg yolk, by using blends of xantophylls or zeaxanthin with one or more pigments such as cantaxanthin, beta-apo-8-carotenal, ethyl ester of the beta-apo-8-carotenoic acid, and extracts from paprika and red peppers. Rosenberg work determined that it is a requirement to use a red pigment in order to obtain more intense orange or reddish hues, as compared with the hues obtained if only yellow xantophylls were used, because of the synergistic effect obtained when both pigments are used.
A great amount of research has been carried out tying to determine the different proportions of yellow xanthophylls and red pigments in order to obtain specific hues in the broiler skin and in egg yolk (Boushy, Foodstuffs, January, 1989). Among them, the works of Quackenbush (1965 Journal of the .A.O.A.C., 48(6):1241-1244) and Marusich (1976 Poultry Science, 55:1486-1494) are of importance because they shown that the zeaxanthin is a more efficient pigmentation than lutein, besides of imparting an orange hue to the broiler skin.
According to the requirements of specific markets for broilers and egg yolk pigmentation, different strategies are observed. For instance, in Mexico it is preferred to saturate the broiler skin with yellow pigment and then supplement with red xantophylls in order to obtain orange hues. To obtain the desired orange hue, a dosage of 60 to 70 ppm. of marigold xantophylls, together with 5 to 10 ppm. of yellow corn gluten xantophylls, and from 2 to 5 ppm. of cantaxanthin or an equivalent red pigment, are added to the feed.
In other countries, such as in the USA, Argentina, Chile, Spain, Portugal, France and Austria, the market prefers a more yellowish tone taking advantage of red xantophylls to obtain a more intense hue. This is obtained by dosing from 10 to 15 ppm. of yellow corn gluten xantophylls, 5 to 22 ppm. of marigold xantophylls, and 0 to 3 ppm. of cantaxanthin or an equivalent red pigment in the broiler feed.
Traditional sources of yellow xantophylls are: alfalfa, yellow corn, yellow corn gluten, and marigold meal concentrates, wherein it has been demonstrated that the saponified natural pigment has a better bioavailability than the non saponified pigment (Wagstaff, 1984; Fletcher, 1986, Poultry Science 65:1708-1714).
The synthetic red pigment more frequently used, is cantaxanthin (Hoffman-La Roche, BASF), but this is very expensive and the pigmentation obtained with it, is not satisfactory. The use of this pigment in Japan and Australia seems to be limited. There are also natural red sources as the capsanthin (paprika or red pepper) and synthetic yellow sources, like the ethyl ester of the beta-apo-8-carotenoic acid (Hoffman-La Roche) and the synthetic citranaxanthin (BASF).
It has been recently reported the preparation of a saponified marigold extract with a high content of zeaxanthin called Hi-Gold which is a trademark of industrial Organica, S.A. de C.V., obtained by a process for the isomerization of lutein contained in the extract, as is described in Torres et al U.S. Pat. No 5,523,494 issued in June 1996.
That patent describes the application of Hi-Gold for broiler skin and egg yolks pigmentation purposes eliminating the use of red pigments. Besides, it is demonstrated that by using Hi-Gold, deeper hues are obtained in broiler skin and egg yolk than those obtained when only the traditionally yellow pigments are used alone.